This invention relates to apparatus for improving video sound.
Commonly, televisions are provided with a single speaker or with a pair of left and right speakers, which are designed to project sound towards a viewer. External speakers may be spaced at some distance to either side of a television set. Speakers may also be provided which reflect, or partially reflect, sound from the walls of a room to the viewer.
"Surround sound" systems have two or more pairs of speakers, one pair of which is located behind the viewer, and the remaining speakers reproducing left and right stereo signals with or without a center monophonic channel. Similarly, the "dyna quad" system has two rear and two front speakers, with the rear speakers connected such that the positive input of one speaker is connected to the left positive output of an amplifier, and the negative input to the right positive output of the amplifier (to provide an L-R signal); the other speaker is connected between the same two outputs but in the opposite polarity, to produce an R-L signal. Both of these approaches attempt to improve the spatial presentation of video programming by adding a rear channel.